The A55T and K153R polymorphisms of MSTN gene are associated with the strength training-induced muscle hypertrophy among Han Chinese men

Myostatin, encoded by the MSTN gene, is a strong regulator of skeletal muscle growth. The present study aimed to investigate whether the A55T and K153R polymorphisms of MSTN were associated with the strength training-induced muscle hypertrophy among Han Chinese men. A total of 94 healthy, untrained men were recruited for an 8-week strength training programme. The thicknesses of biceps and quadriceps, along with anthropometric measurements of the participants, were assessed before and after the programme. The MSTN polymorphisms were subsequently genotyped employing polymerase chain reaction-restriction fragment length polymorphism technique and confirmed by DNA sequencing. One-way analysis of variance was used to compare the pre- and post-training measurements between carriers of different polymorphic genotypes. Our results indicated that individuals with AT+TT genotype of the A55T polymorphism showed a significant increase in the thickness of biceps (0.292 +/- 0.210cm, P=0.03), but not quadriceps (0.254 +/- 0.198cm, P=0.07), compared to carriers of AA genotype. For the K153R polymorphism, the increases in the thicknesses of both biceps (0.300 +/- 0.131cm) and quadriceps (0.421 +/- 0.281cm) were significantly higher among individuals with KR than those with KK genotypes (P<0.01 for both muscles). The results obtained therefore suggested a possible association between the two polymorphisms and the strength training-induced muscle hypertrophy among men of Han Chinese ethnicity.